Oil burners of the low pressure type



Nom 22, 1955 R. R. WITHERELL OIL BURNERS OF THE LOW PRESSURE TYPE Filed June 28 1951 mz\ 72' um, A '04 f I INVENTOR. M, /Poaa'r A. W/THERELL 4 Sheets-Sheet l New0 22, 1955 R. R. WITHERELI.

OIL. BURNERS OF THE LOW PRESSURE TYPE 4 Sheets-Sheet 2 Filed June 28, 1951 llziw INVENTOR. ROBERT lflmfeu NOV. 22, 1955 R. R. WITHERELL OL BURNERS OF THE LOW PRESSURE TYPE 4 Sheets-Sheet I5 Filed June 2.8, 1951 ifigg' A sans NGV- 22, 1955 R. R. WITHERELL 2,724,433

OIL BURNEIRS OF THE`LOW PRESSURE TYPE Filed June 28 1951 4 Sheets-Sheet 4 INVENTOR.

2,724,433 Patented Nov. 22, 1955 United States Patent Otiice oIL BURNERS or THE Low PRESSURE TYPE Robert R. Witherell, Bloomington, Ill., assigner, by mesne assignments, to Henney Motor Company, lne., New York, N. Y., a corporation of New York Application June 2S, 1951, Serial No. 234,084 19 Claims. (ci. 15s-36.3)

This invention relates to fuel and air pumping arrangements for liquid fuel burning systems and has particular reference to oil burners of the low pressure type in which oil and air are supplied under relatively low pressures to a mixing nozzle which mixes the oil and air supplied thereto and discharges such mixture of oil and air in the form of a spray of iinelydivided oil particles.

This invention has particular reference toa liquid fuel burning system of this type which is much simpler in construction and much less expensive to manufacture than oil burners of this type as `now manufactured and sold. As a matter of fact, the low pressure fuel burning system herein disclosed is of such a simple nature and construction that it will be possible to manufacture and sell low pressure oil burners embodying this invention at a` price which will be competitive with high pressure burners. t`

A principal object of the invention, therefore, is to provide a liquid fuel burning system of the low pressure type which is simple in construction, efcient in operation,` and which may be manufactured and sold at a materially lower price than that at,` which burners of this type are now marketed. t t

Another object of the invention is to provide a liquid fuel burner of the low pressure type which is adapted efficiently to burn fuel at relatively low rates and which burner is simple in construction, thereby making it possible to use this burner in connection with low cost heating systems having a heat output of the order of 70,000 B. t. u. per hour.

Other and further objects of the invention will be` apparent from the following description and claims and may be understood by reference to the accompanying drawings, of which there are four sheets, which by way` of illustration show preferred embodiments of the invention and what I now consider to be` the best mode in which I have contemplated-applying the principles lof my invention. Other embodiments of the invention may be used without departing from the scope of the present invention as set forth inthe appended claims.

Inthe drawings:

Fig. 1 is a schematic view of a fuel burning system` embodying the invention;

Fig. `2 is a fragmentary view illustrating a modified form of the invention;

Fig. 3 is a sectional `view of the air pump taken along the line 3-3 of Fig. l; r

t Fig. 4 is a schematic fragmentary view illustrating a modified form of the invention, taken generally along the line 4--4 of Fig. 5;

Fig. 5 is a plan view ofthe apparatus illustrated in Fig. 4; t

Fig. 6 is a fragmentary side elevational view, looking inthe direction of the arrow B in Fig. 4; j

` Fig. 7 is an enlarged sectional viewof the nozzle illustrated in Fig. 4;

Fig. 8 is across sectional view taken along the line 8 8 of Fig. 7; and

Fig. 9 is a face view of an inner part of the nozzle illustrating the converging oil and air passages thereof.

As` shown in Fig. 1, an oil burner embodying the in' vention comprises a reservoir 10 for containing a body of oil 12 and air under pressure, motor driven air pump means 14 discharging into such reservoir so as to accumulate therein a mass of air under pressure above and in contact with the oil therein, an oil and air mixing nozzle indicated generally at 16 having restricted converging oil and air passageways so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of an oil fog, a uid connection 18 between such body of oil and the oil passageway of the nozzle and operable for supplying oil to the nozzle in response to the pressure to which the oil in said reservoir is subjected by the air discharged by said air pump means, a fluid connection 20 between said reservoir and the air passageway of the nozzle 16 for supplying air under pressure thereto, and means comprising an oil injector 22 actuated by the air discharged into said reservoir by the air pump means 14 for supplying oil to the reservoir through the oil supply line 24 and under the control of a float valve indicated generally at 26.

The nozzle 16 may be of the construction shownin Williams Patent No. 1,934,755, issued November 14, 1933, for Burner Assembly, and as diagrammatically illustrated in Fig. l, includes oil passageways 30supplied with oil through the line 18 and arranged to discharge jets of oil into `the air passages 32 which are supplied with air through the air line 20 at substantially the same pressure as that at which oil is supplied to the nozzle through the line 18. The oil and air passages 30 and 32 thus converge so `as to mix the oil and air, which mixture then flows into the tip chamber 34 and then is discharged over the `knife edge oriiice 36 thereof in the form of a spray of nely divided oil particles into a stream of secondary air.

The nozzle 16 is arranged in an air cone 38 which in turn is arranged in an outer air cone 40, which in turn is arranged in `and at the outer end of an air supply pipe 42` ow into such cones `from the tube 42, and the forwardy ends of the air cones are frusto-conical, as indicated at 50 and 52, so as to direct the streams of secondary air which ow through the air cones 38and 40 into the spray of iinely divided oil particles discharged by the nozzle 16 so as to form with such spray a combustible mixture which may be ignited by an electric ignition system including a pair of spaced electrodes 54. i

The reservoir 1l) may comprise a suitable container having secured tothe upper end thereof a frame or casting 60 which closes the top of the reservoir 10 and forms a support for the pump 14 and for an electric motor indicated generally at 62. The pump 14 may be of the rotary sliding vane type and include a cylinder 64 having a rotor 66 rotatable therein and provided with a series of radial slots 68 in each of which a vane 70 is arranged. The rotor 66 `is fixed for rotation on the end of the shaft 72 of the motor, and upon rotation of the rotor 66 air will be drawn the oil `injector 22 for actuating the same. The line 24 forv supplying oil from a storage tank to the reservoir 10 opens into the throat 8i) of the injector so thatduring operation ofthe pump 14 the jet of air supplied to the injector 22 t will cause a flow of oil through the line 24 into the injector 22 and from which it is discharged along with the air from the pump into the reservoir 10.

The air line for supplying air under pressure to the nozzle may bc lconnected to one end of a duct 82 formed in the casting v1 and the duct S2 communicates through a passage 84 with a passage or pipe 86 which opens into the upper part of the reservoir so that air under pressure may ilow from the reservoir through the line 2t) to the air supply passage of the nozzle. The air passages of the nozzle are restrictedy so that primary air at the proper pressure and in adequate amounts will be supplied to the nozzle for mixture with the oil supplied thereto so as to form a primary. mixture of oil and air. The passages 86 and 84 form part of a bypass between the inlet and discharge sides of the pump and which further includes the passage 88, the chamber 90, and the passage 92 which leads to the inlet 74 of the pump.

The air supply passage 92 leading to the inlet 74 is provided withla valve chamber 96 for a check valve 98 so that when the pump 14 is not operating, air from the reservoir 10 may not escape through the pump and through the inlet thereof to atmosphere. The other end of the passage 92 communicates with the chamber 90 which is provided `with a series of air inlet openings 100 communicating with the interior of the casing of the motor 62, and which casing in turn is provided with a series of air inlets 102 so that air for the pump 14 is supplied through the openings 102, 100, the chamber 90, and the passage 92.. v

An adjustable air metering valve 104 cooperable with a valve seat 106 formed between the passages 84V and 88 may be provided to control the by-passing of air from the outlet side of the pump to the inlet side thereof. This control also will regulate the air pressure in the reservoir Y' 10. VAir is always free to ow through the line 20 and the air passages ot" the nozzle and to escape from the nozzle' 16-s0 that at the end of the cycle of burner operation the air under pressure in reservoir will be dissipated through the nozzle 16 so as to purge the same of oil.

The oil line 18 which supplies oil to the nozzle 16 may be Vconnected to a duct 110 formed in the casting 60, and this duct is Connected by pipe 112 to the body of oil in the bottom of the reservoir 10 whereby the air pressure in the reservoir 10 will cause oil to ow through the pipe 112, the duct 110 and the line 18 to the nozzle 16. A calibrated oriiice'11'4 may befarranged in the connection between the line 18 and the duct 110 so as to meter the flow of oil to the nozzle, and this forms a metering means for metering the Viiow of oil to the nozzle. Other forms of metering means may be employed for this purpose, or the oil passagesi-nthe nozzle may be so restricted as to perform this metering function. In any event, the ilow of oil to the nozzle v16 is so regulated that the primary mixture of oil and aifr discharged by the nozzle will mix with the secondary air stream so as to form a combustible mixture. In

' some cases it may not be necessary to employ a fan for supplying a secondary air stream.

' The shaftA 72 is connected to the rotor of the motor so that the motor 62 will drive the air pump 14, and such shaft is journalled in bearing 116 supported in the frame or casting 60. The bearing 116 may form part of a s0- called oilless bearing.

' The. injector 22 will discharge a mixture of oil and air into the reservoir 10, and some particles of the oil so discharged will remain in suspension and be carried through the vpipe 86, the passage 84, and the passage 88 into the chamber 90 and thence downwardly through the shaft opening in the pump and also through the passage 92 into the pump for lubricating the pump.

The oil line 24 is connected to the oat valve 26, which in turn `is connected to another oil supply line l120 which is connected with a suitable oil storage reservoir. Thel float valve 26 `includes an annular seat 122, a ball valve 124 adapted to seat on the seat 122 so asto close the` valve, ak spring 126y which biases the ball valve 124 to its seat, and a pin 128 which is adapted to project through the valve seat and engage the ball valve member 124 for unseating the same. A float 130 is pivoted at 132 and has an arm 134 engageable with the pin 128 for raising the same when the level of oil in the reservoir falls below a predetermined minimum, thereby to open the valve 26 and permit the application of suction at the throat of the venturi of the injector 22 to the oil line 24 so as to cause oil to ow through the line 120, the valve 26 and the passage 24 into the injector 22, from whence it is discharged into the reservoir 10. When the level of oil 12 in the reservoir reaches a predeterminedv elevation, the tloat will rise and permit the spring 126 to seat the ball valve member 124 and to shut off the supply of oil to the reservoir. The oat valve 26 together with the injector 22 thus forms a means for maintaining a predetermined amount of oil in the reservoir 10.

In the modication shown in Fig. 2 the arrangement is the same except that a different form of injector is shown and also except for a different arrangement for lubricating the air pump 14, and hence similar reference characters are used in Fig. 2 to indicate the parts corresponding with those shown in Fig. l.

In the case of Fig. 2, the pump shaft 172 is provided with a spiral groove 174 which extends between annular grooves 176 and 178. A cross duct 180 connects annular groove 178 with axial duct 182 which at its lower end opens into a chamber 184 that communicates with a duct 186. A pipe 188 depending into the oil 12 in the reservoir 10 is adapted to supply oil from the body 12 to the duct 186 and thence upwardly through the passage 182 and the cross duct to the annular groove 178. Upon rotation of the motor shaft 172 the spiral groove 174 cooperating with the bearing 190 will cause oil to ow upwardly along the shaft for lubricating the bearing and thence into the groove 176, from which it escapes into the oil slinger 192 which discharges the oil into a chamber 194, the lower part of which contains packing material and which permits the flow of oil into the pump inlet chamber 196. The pump inlet 74 communicates with the pump inlet chamber 196 which, like Fig. 1, is supplied with air through openings 100 and 102 in the motor casing.

A hardened steel ball 200 positioned by a screw 202 in the chamber 184 is engageable with a socket in the end of the motor shaft 172 so as to form a thrust bearing for the shaft 172, the walls of the socket being relieved so as to permit iiow of oil from the chamber 184 upwardly through the axial duct 182 in the shaft 172. The vshaft 172 may also be provided with several cross ducts 204 for supplying lubricant to the interior of the pump 14. Some of the lubricant which is returned to the pump inlet chamber 196 from the chamber 194 will flow into the pump through the opening therein through which the shaft 172 extends for lubricating the pump, and other parts of the oil from the chamber 196 will flow into the 4pui-np through the; inlet 74 thereof for lubricating and sealing the working parts of the pump.

The 'construction' and loperation of the embodiment shown in Fig. 2 otherwise will be the same as that shown in Fig. l, it being understood that some means, such as previously mentioned, are employed for metering the supply of oil to the nozzle 16.

It is contemplated that suitable electrical controls will be provided for the burner so as to drive the motor 62 and the fan 44 simultaneously and so as to energize the ignition electrodes 54 at the beginning of the burner cycle of operation so as to ignite the combustible mixture formed by the spray discharged by the nozzle 16 and the secondary air stream.

In the moditicationy illustrated in Figs. 4 to 9' inclusive the reservoir 210 for containing a body of oil 212 and air under pressure is closed at its top by a casting lor block 214 which lforms a bearing and support fora motor indicated:l generallyv at 216, such for example as afractional horsepower shaded pole motor. The reservoir 210 is partially enclosed `by a casing 218 to the front of which an `air tube 220 is secured. The casing 218 includes a cap 222 which encloses` the motor 216 and forms a fan chamber 224 above the motor and an annular passage 226 which delivers air fromthe fan chamber downwardly over the outside of the motor 216 and into the casing 218.

`A `series of vanes 228 projecting outwardly from the motor spaces the same from the cap 222 and may also serveas air deectors and a means for dissipating the heat of the motor into the air which flows downwardly through the annular passage 226. p

The shaft 230 of the` motor is journalled in a bearing 232 formed in the block214 and a fan wheel 234 is secured to the upper end of the shaft 230 and within the fan chamber 224. The fan chamber is provided with an air inlet 236. The casing 218 maybe provided with a means, such as a rotary disc valve 238, for regulating the amount of air delivered by the fan 234 to the air tube 220. A rotary air pump indicated generally at 240 of construction like that disclosed in Fig. 3 is mounted in the reservoir 210 and on the under side of the block 214, and the rotor 242 thereof is keyed to the lower end of the motor shaft `230 `so as to be driven thereby simultaneously with the operation of the fan 234. p

The inlet 244 to `the air pump 240 communicates through a lter 246 with the interior of the motor, and air from the fan chamber 224 is supplied to the interior of the motor through the gap 248 around the shaft 230 in the top Wall of the motor casing. A conduit 250 conducts air discharged by the air pump 240` to a jet 252 which discharges into the throat of the venturi of an injector indicated generally at 254. An oil supply line 256 communicates at one end with the throat of the venturi of the injector 254 and leads to an oil supply reservoir. The line 256` includes a valve chamber 258 having valve seat 260 `and a valve member 262 therein. A spring 264 biases the valve member 262 to seat on the seat 260 so as to shut olf the flow of oil through the line 256to the injector 254. p

The valve member 262 is carried by a reciprocal valve rod 266, the lower end of which rests upon lever 268 pivoted at` one end to a stationary pivot 270. The other end ofthe lever `268 is `pivoted to a cup or open float 272 which is adapted to oat in the body of oil 212 in the reservoir 210. A guide rod 274 carried by and pro jecting upwardly from the cup 272 is slidable in a guide 276. A conduit 278 connected to `the discharge `side of the injector 254 empties into the cup 272.

During operation of the air pump, with the parts arranged as shown in Fig. 4 the jet of air discharged from the jet 252 will draw oil through the line 256 and discharge the same with the air through the conduit 278 into the cup 27 2. When the level of oil in the cup 272 reaches a predetermined value, the mass of the cup 272 andthe oil therein will cause the cup 272 to sink in the oil 212 to a point until the rod 266 will have moved downwardly sufficient to permit the spring 264 to seat the valve member 262 and shut off the flow of oil through the line 256. An oil conduit 280 :at one end terminates inside the cup 272 and at its other end 282 is in communication with oil passage or tube 284 in the` nozzle indicated generally at 290.

The oil discharged from the conduit 278 willaccumulate in the cup 272 while theair discharged from the conduit will accumulate in the reservoir 210, and when The air passages 294 are restricted so that air `will `accumulate in the reservoir 210 to the desired pressure, say

i suicient pressure `is attained therein suchtpressure will p 6 for example a pressure of the order of two to three pounds per square inch. i

The embodiment illustrated in Fig. 4 may be provided with a means similar to that shown in Fig. 1 for regulating the pressure within the reservoir 210. When a sufficient amount of oil has been withdrawn from the cup 272,` the same will rise due to the buoyancy thereof, which will unseat the valve member 262 thereby permitting the injector 254 to draw oil into the reservoir 210 and deliver the same into the cup 272. An oil line 300, the lower end of which terminates below the level of the body of oil 212, leads to the bearing 232 for supplying oil to the same, and from this `bearing oil is returned through the lter 246 and through the duct 302 to the interior of the air pump 240 which serves to lubricate the same.

The casing 218 and the air tube 220 house the nozzle 290 and the air and oil lines which supply air and oil to the same. The nozzle, like those illustrated in the previous modications, is arranged to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles into a secondary stream of air which is supplied by the fan 234 through the air tube 220.` An air cone 304 may be arranged at the outer end of the air tube 220 so as to tend to converge the air stream into the conical spray of nely divided oil particles issu-` ing from the nozzle 290.

As shown in Figs. 7, 8 and 9, the nozzle 290 consists of an outer cap 306 and an inner member 308, the outer cap having a knife edge orifice 310 therein. The member 308 is of such shape as to leave between it and the cap 306 a plurality of air passages 312 which are supplied with air from the space 314 in back `of the member 308, the space 314 communicating with an air pipe 316 which in turn is mounted in and communicates with the interior of a hollow member 318 to` the interior of which the air line 292 is connected. The member 308 is seated inside the cap 306 `and cooperates therewith to define an annular tip chamber 320 within the orice 310. The air passages 312 at their forward ends terminate in an annular chamber 322, `and the air slots or passage 294 extend between the chambers 322 and 320.

The oil pipe 284 delivers oil into a cavity in the member 308 within which a metering plug 324 is arranged,

the metering plug having a metering orifice 326 for meter-` ing the llow of oil from the pple 284 into the oil passages,

328. p The oil passages 328 extend between the cavity in the member 308 on the downstream side of the metering orifice 326 and the air passages 294. Thus the air pa'ssages 294 and the oil passages 328 converge, and the oil passages discharge jets of oil into the air streams owing through the air passages 294. The oil and air are discharged from the passages 294 into the tip chamber 320 in a tangential manner so that the 'oil and air mixture' will swirl therein and then break over the knife edgeof the orifice 310 and be discharged in the form of` a conical spray of nely divided oil particles into the secondary air stream issuing from the air cone 304 and mix therewith to form a combustible mixture.

The oil and air are supplied to the passages 294 and 328 at substantially the same pressure, which may be a pressure of the order of two to three pounds per square inch when the initial mixing of the oil and air takes place t in the passages 294 and the tip chamber 320.

The arrangement disclosed in Fig. 4 for feeding oil from `the reservoir 210 to the nozzle 290 enables the burner to become operative without priming, afterrunning out of oil, since the oil supplied to the nozzle is taken from the inside of the cup 272 which, when ernptied,` becomes buoyant and unseats the valve member 262 so that the air pump 240 will be operative to elfect the flow of oil through the oil supply line 256 into the cup 272.

This application is a continuation-impart yof lmy prior cop'ending application Serial No. 195,371, tiled November 13, 1950, now abandoned, for Fuel and Air Pumping Arrangements for Oil Burners of the Low Pressure Type.

l While I havey illustrated and described preferred embodiments of myY invention, it is understood that these are capable of modification and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

1. A fuel and air pumping arrangement for supplying oil and air to the nozzle of a low pressure type oil burner comprising a reservoir for containing a body of oil and air under pressure, motor driven air pump means discharging into such reservoir so as to accumulate therein a mass of air under pressure above and in contact with the oil therein, means associated with said reservoir and pump means for regulating the air pressure in said reservoir during operation of said pump means, a duid connection through which oil is supplied from said body of oil to said nozzle in response to the pressure to which the Voilin said reservoir is subjected by the air discharged by said air pump means, a fluid connection through which air is supplied from the mass accumulated in said reservoirto said nozzle, and means actuated by the air as it is discharged into said reservoir by said air pump means for supplying oil to said reservoir.

2. A fuel and air pumping arrangement according to claim l including oil level responsive means arranged to control the operation of said means for supplying oil to said reservoir.

3. A fuel and air pumping arrangement according to claim 1 wherein said oil supplying means include an injector connected to said air pump means so as to be actuated by the air pumped thereby, an-d an oil supply line in communication with the throat of said injector.

4. A fuel and air pumping arrangement according to claim l wherein said o-il supplying means include an in jector connected to said air pump means so as to be actuated bythe air pumped thereby, an oil supply line in communication with the throat of said injector, a valve in said `oil supply line, and a oat responsive device in the oil in said reservoir arranged so as to cause opening of said valve when the vlevel of oil in sai-d reservoir falls below a predetermined level so that the suction at the throat of said injector is effective to cause flow of oil through the oil supply line into said reservoir.

5. A fuel and air pumping arrangement for supplying oil and air to the nozzle of a low pressure oil burner comprising a reservoir for containing a 'body of oil and air under pressure, a vmotor driven rotary air pump discharging into such reservoir vso as to accumulate therein a mass of air under pressure above and in contact with the oil therein, means associated with said reservoir and pump for `regulating the air pressure in said reservoir during operation of ysaid pump, an oil and air mixing nozzle having restricted, converging oil and air passageways so as to mix the oil' and air supplied thereto and to discharge such mixture of oil and air in the form of an oil fog, a fluid connection between said body of oil and said oil passageway vof said nozzle for supplying oil thereto, a iluid connection between said reservoir and said air passageway of said nozzle for supplying air under pressure thereto, an oil injector connected with the discharge side of said pump so that the air discharged by said pump functions as a jet for operating said injector, an oil supply line in communication with the throat of said injector so that during operation of said air pump said injector will function to draw oil into said reservoir, and means controlling the operation of said injector so as to maintain a predetermined amount of oil in said reservoir.`

6. A fuel and air Vpumping arrangement for supplying oil 'and air to the nozzle of a low pressure oil burner 8 comprising a reservoir for containing a body of oil and air under pressure, air pump means discharging into such reservoir so as to accumulate therein a mass of air under pressure above and in contact with the oil therein, means associated with said reservoir and pump means for reguating the air pressure in said reservoir during operation of said pump means, and an oil and air mixing nozzle constructed and arranged so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of nely divided oil particles, an oil line between said body of oil and said nozzle for supf plying oil thereto, a uid connection between said reservoir and said nozzle for supplying air under pressure thereto, means utilizing the air as it is discharged by said air pump means for supplying oil to said reservoir, and means for supplying a secondary stream of air for mixture with the spray of oil particles.

7. A fuel and air pumping arrangement for supplying oil and air to the nozzle of a low pressure oil burnery cornprising a reservoir for containing a body of oil and air under pressure, air pump means discharging into such reservoir so as to accumulate therein a mass of air under pressure above and in contact with the oil therein, means associated with said reservoir and pump means for regulating the air pressure in said reservoir during operation of said pump means, an oil and air mixing nozzle constructed so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles, a fluid connection between said'body of oil and said nozzle for supplying oil thereto, a uid connection between said reservoir and said nozzle for supplying air under pressure thereto, and means actuated by the air as it is pumped by said air pump means for pumping oil into said reservoir.

8. A fuel Aand air pumping arrangement for an oil burner comprising a reservoir for containing a body of Oil under pressure, pump means disposed in and discharging into such reservoir so as to subject the oil therein to pressure, means associated with said reservoir and pump means for regulating the air pressure in said reservoir during operation of said pump means, and'means disposed in said reservoir and actuated by the discharge of said pump means for pumping oil into said reservoir.

9, A fuel and air pumping arrangement for supplying oil and air to the nozzle of a low pressure oil burner comprising a reservoir for containing a body of oil *under pressure, air pump means discharging into such reservoir so as to subject the oil therein to pressure, means associated with said reservoir and pump means for regulating the air pressure in said reservoir during operation of said pump means, an oil and air mixing nozzle constructed so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles, a fluid connection between said body of oil and said nozzle for supplying oil thereto in response to the pressure in said reservoir, a uid connection between said air pump and said nozzle for supplying air under pressure thereto, and means actuated by the air as kit is pumped by said air pump means for pumping oil into said reservoir.

1.0. A fuel and air pumping arrangement for supplying oil and air to the nozzle of a low pressure oil burner comprising a reservoir for containing a bodyof oil andl air under pressure, an air pump mounted on said reser` voir and having its discharge connected with said reservoir so as to subject the oil therein to pressure, means associated with said reservoir and pump for regulating the air pressure in said reservoir during operation of said pump, an oil and air mixing nozzle constructed lso as to ,mixthe oil and air supplied thereto and to discharge such mixture of oil and air .in the form of a spray of inely divided oil particles, a fluid connection between saidbody of oil and Said nozzle for supplying oil thereto in response to the pressure in said reservoir, a fluid connection between said air pump and said nozzle Afor suptrai oil into said reservoir.

1l; An oil burner comprising a reservoir for containing oil and air under pressure, `an air pump arranged to discharge into such reservoir so as to accumulate therein amass of air under` pressure above and in contact with the oilthereimmeans associated with said reservoir and pump forfregulating the air pressure in said reservoir during operation of said pump, an oil and air mixing nozzle having convergingoil and air passageways arranged so as to `mix the oil and air supplied thereto and to discharge such mixture of oil and air` in the form of a spray of iinely divided oil particles, a fluid connection between said reservoir and said oil passageway of said nozzle and operable for. supplying oil thereto, aconnec- `tion between said reservoir and said air passageway of said nozzle for supplying air under pressure thereto, and `mea`ns including an injector connected to said air pump so` as to be actuated by `the air as it is pumped thereby for supplying oil to said reservoir,` an oil supply line opening into the throat ofsaid injector, a valve in said oil supply line, an open oat in the oil in said reservoir connected to said valve for opening said valve whenthe level of oil in said oat falls below a predetermined level, said open oat being arranged to accumulate `therein at least part of the o`il discharged by said injector and said fluid connection terminating inside of said iioat so that i oilgis supplied from the accumulation thereof in said `tloat through said tluid connection to said nozzle in response to the `pressure to which the oil in said float is subjected by the airrdischarged by said air pump.

12. An oil burner comprising a reservoir for containing oil `and air under pressure, amotor driven air pump in such reservoir arranged to discharge into such reservoir so as to accumulate therein amass of air under pressure above and in contact with the oil therein, means associated with said reservoir and pump for regulating thejairpressure` in said reservoir `during operation of said pump, an oil and air mixing nozzle l having converging oil and air passageways arranged so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles, a huid connection between said reservoir andsaid oil passageway of said nozzle and operable for supplying oil thereto, a connection between said reservoir and said air passageway of said nozzle for supplying air under pressure thereto, an injector actuated by the air discharged by said pump for supplying oil to said reservoir, an oil supply line opening into the throat `of said injector, a valve in said oil supply line, an open floatin the oil in said reservoir connected to said valve for opening said valve when the level of oil in said float falls below a. predetermined level, said open oat being arranged to accumulate therein at least part of the oil discharged by said injector and said fluid connectionterminating inside of said floatso that oil is supplied from the accumulationthereof in said tioat through said uid connection to said nozzle in response to the pressure to which the oil in said tloat is subjected by the air discharged by said air pump.

13. An oil burner comprising a reservoir for con- `taining oil and air under pressure, an air pump arranged to discharge into such reservoir so as to accumulate therein a mass of air under pressure above and in contact with the oil therein, means associated with said reservoir and pump for regulating the air pressure in said reservoir during operation of said pump, an oil and air` mixing nozzle having converging oil and air passage ways arranged so as to mix the oil and air supplied `thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles, a tluid connection between said reservoir and said oil passageway of said nozzle and operable for supplying oil thereto, a

, connection between said reservoir and saidair passageway of said nozzle for supplying air under pressure thereto, and means including an injector connected to said air pump so as to be actuated by the air pumped thereby for supplying oil to said reservoir, :an oil supply line opening into the throat of said injector, a normally closed valve in said oil supply line, an open iloat in the oil in said reservoir connected to said valve for opening said valve when the level of oil in said ioat falls below a predetermined level, said open tloat being arranged to accumulate therein at least part of the oil discharged by said injector and said fluid connection terminating inside of said oat so that oil is supplied4 from the accumulation thereof in said tloat through said uid connection to said nozzle in response to the pressure to which the oil in said oat is subjected by the air discharged by said air pump, and means in said nozzle upstream relative to said converging passageways for metering the supply of oil to said converging passageways.

14. An oil burner comprising a reservoir adapted to contain a body of oil and air under pressure, means operable to accumulate a mass of air under relatively low pressure in said reservoir, an injector operated by said means for supplying oil to said reservoir, an oil supply line oil line for controlling the flow of oil therethrough, an open float arranged to accumulate oil discharged from said injector and to float in the body of oil in said reservoir, an oil and air mixing nozzle having restricted, converging oil and air passageways so as to mix the oil and airsupplied thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles, a fluid connection between the oil accumulated in said open float and said oil passageway of said nozzle for supplying oil thereto under the pressure of `the air in said reservoir, a connection between said reservoir` and said air passageway of said nozzle for supplying air under pressure thereto, said duid connection having means associated therewith for meteringthe supply of oil therethrough to said `nozzle.`

` l5. An oil burner comprising a reservoir adapted to contain a body of oil and air under pressure, means operable to accumulate a mass of air under relatively low pressure in said reservoir, an injector operated by said means for supplying oil to said reservoir, an oil supply line opening into the throat of said injector, a valve vin said oil line for controlling the flow of oil therethrough, an open float arranged to accumulate oil discharged from said injector and to lloat in the body of oil in said reservoir, an oil and air mixing nozzle having converging oil and air passageways so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of nely divided oil particles, a uid connection between the oil accumulated in said open float and said oil passageway of said nozzle for supplying oil thereto under the pressure of the air in said reservoir, and a connection between said reservoir and said air passageway of said nozzle for supplying air under pressure thereto.

16. An oil burner comprising a reservoir adapted to contain a body of oil and air under pressure, means operable to accumulate a mass of air under relatively low pressure in said reservoir, an injector operated by said means for supplying oil to said reservoir, an toil supply line in communication with the throat of said injector so as to cause oil to ow through said line into said reservoir, means for controlling the flow of oil through said line so as to maintain oil in said reservoir within minimum and `maximum limits, an oil and air mixing nozzle having said reservoir and said air passageway of said nozzle for supplying air under pressure thereto.

17. An oil burner comprising a reservoir for containing oil and air under pressure, a motor driven air pump arranged to discharge into such reservoir so` as to accumulate therein a mass yof air under pressure above and in contact with the oil therein, means associated with said reservoir and pump for regulating thev airpressure in said reservoir during operation of said pump, an oil and air mixing nozzle having converging oil and air passageways arranged so as to mix the oil and air supplied thereto and to discharge such mixture of oil and air in the form of a spray of finely divided oil particles, a uid connection between said reservoir and said oil passageway of said nozzle and operable for supplying oil thereto, a connection betweenvsaid reservoir and said air passageway of said nozzle for supplying air under pressure thereto, and means including `an injector connected to said air pump so as to be actuated by the air pumped thereby for supplying oil to said reservoir, an oil supply line opening into the throat of said injector, a valve in said oil supply line, and a float in the oil in said reservoir connected to said valve for opening said valve when the level of oil in said reservoir falls below a predetermined level.

18. A fuel and air pumping arrangement for an oil burner comprising a reservoir for containing a body` of oil and air under pressure, motor driven air pump means discharging into such reservoir so as to accumulate therein a mass lof air under pressure above and in contact with the oil therein, means associated with said reservoir and pump means for regulating the air pressure in said reservoir during operation of said pump means, an oil and air mixing nozzle having restricted, converging oil and air 12 plying air under pressure thereto, and means including an injector connected to said air pump means soas to be actuated by the air pumped thereby for supplyingoil tok said reservoir, an oil supply line opening into the throat of said injector, a valve in said oil supply line, and an open float in the oil in said reservoir connected to said valve for opening said valve when the level of oil in Asaid oat falls below a predetermined level, said open float being arranged to accumulate therein at least part of the oil discharged by said injector and said uid ,connection terminating inside of said float.

19. A fuel and air pumping arrangement for an oil burner comprising a reservoir for containing a body of oil under pressure, air pump means disposed in and discharging into such reservoir so as to subject the oil there in to pressure, means associated with said reservoir and pump means for regulating the air pressure in said reservoir during operation of said pump means, and an injector having an oil supply line connected to its throat and connected to said air pump means so that the air as it is discharged thereby energizes said injector to pump oil dur ing the operation of said air pump means, said injector being arranged to discharge the oil pumped thereby into said reservoir.

References Cited in the file of this patent UNITED STATES PATENTS Conery Oct. 28, 1952 

